Homeowners and builders seeking to renovate or restore existing homes often wish to alter the existing windows or window frames. In some cases the old decorative portion of the window frame is removed or replaced, either as a consequence of replacing a window, or simply in order to renovate the “look” of an old window. In such cases the window is mounted into an existing (or similar) structural portion of the window frame, leaving a gap between the mounted window and this structural portion of the frame (usually made of metal such as steel or aluminum alloys) into which it is mounted.
Such a resulting gap can be non-uniform, such that it is larger on one side or another, or at the top or bottom. While installers may be able to center the windows during installation, an aesthetically acceptable centering is not always possible. Additionally, the gap at the top of the window is often wider than the gap at the bottom, and centering from top to bottom is more difficult.
As one way of improving the cosmetic appeal of such window installations or window frames and filling the gaps between windows and structural frames installers have used flat polymeric window trim strips to cover the gaps between window and frame. These flat window trim strips may optionally have an adhesive such as an adhesive strip on one side permitting them to be affixed to the underlying metal structural window frame thereby covering or filling the gaps, and are attractively colored or patterned on the front visible decorative surface.
Because the gaps vary in size, manufacturers sell a range of window trim in different widths, which can be used as-is, or cut down to the desired width in the field by the installer. Cutting down a wider trim to the desired width is often preferred by the installers to keeping multiple different widths in inventory. However, the time, inconvenience and skill required to make a uniform cut into a window trim strip can lead to waste, added expense, and aesthetically variable lack of uniformity for the homeowner.
Currently, customizable trim is made by extruding polyvinyl chloride (or a similar polymeric material) through an extrusion die having one or more small tooth on one interior surface. This die thus creates shallow furrows on the bottom surface of the trim; these furrows can then be used as guides for a knife used to cut the trim. However, die-formed furrows have a number of drawbacks, including the potential for accidents resulting from the knife slipping on the trim strip, or sore hands resulting from trying to snap the trim apart after scoring it with the knife. Additionally, the use of extrusion dies to form such grooves produces shrink lines on the side of the trim opposite to the furrows, due to uneven shrinkage of the extruded polymeric material after the extrudate cools down. Such shrink lines are visible on the exposed (“front”) side of the trim after installation, which is aesthetically undesirable. However, there is a trade off in using such furrowed trim strips: the deeper the furrows are (and thus, the easier to cut the trim is), the more prominent the shrink lines on the front surface become.
Accordingly, there is a need in the art for customizable polymeric trim that is easy to cut to a necessary width in the field, but is smooth on the top surface so as to remain aesthetically pleasing. Additionally there is a desire among installers for a trim strip that is faster to install, less dependent on specialized equipment, and which results in less waste and greater aesthetic predictability.
In addition, there is a desire among manufacturers of polymeric window trim for improved methods for making polymeric window trim stripping which is customizable, uniform easy to cut, and smooth on the front surface so as to remain aesthetically pleasing. Such manufacturers particularly value manufacturing methods that have at least one advantage which may include: product uniformity from lot to lot, low cost of manufacture, relatively low equipment capitalization costs through the use of largely pre-existing equipment and materials, and relative simplicity of manufacture.